Jotham potter



(No Model.) G. R LEAN D 'd 2 Sheets-Sheet 1.,

J. POTTER, Administrator. ELECTRIC ARC LAMP.

No. 593,899. Patented Nov. 16,1897.

(No Model.) G R, LEAN, Dec'd, 2 Sheets-Sheet 2.

J. POTTER, Administrator. ELECTRIC ARC LAMP.

No. 593,899. Patented Nov. 16,1891

UNTTED STATES PATENT Orrrcs.

GEORGE It. LEAN, OE CLEVELAND, OI-IIO; .IOTIIAM POTTER, ADMINISTRATOR OF SAID LEAN, DECEASED, ASSIGNOR TO THE JANDUS ELECTRIC COM- PANY, OF SAME PLACE.

ELECTRIC=ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 593,899, dated November 16, 1897.

Application filed January 23, 1897. Serial No. 620,435- (No model.)

To aZZ whom it n-my concern: inner surface of the arc-inclosing globe soon Be itknown that I, GEORGE R. LEAN, a resibecame so coated with carbon as to materident of Cleveland, in the cou'ntyof Cuyahoga ally obscure the light emitted from the adjaand State of Ohio, have invented certain new cent ends of the carbons.

and useful Improvements in Electric-Arc The object of my invention is to obviate Lamps; and I do hereby declare the followthe difficulties and objectionable features iug to be a full, clear, and exact description above noted; and with this end in View the of the invention, such as will enable others invention consists in certain features of conskilled in the art to which it appertains to struction and combinations of parts, as will to make and use the same. be hereinafter set forth, and pointed out in ll'lyinvention relates to an improvementin the claim. electric-arc lamps, and more particularly to In the accompanying drawings, Figure 1 is the construction of the carbons with respect a view of an electric-arc lamp embodying my to the arc to be formed between them and invention. Fig. 2 is an enlarged View of two 1 5 to the regulating mechanism for controlling electrodes exemplifying my invention. Fig. their separation. 3 is a view showing the effect of the use of To insure the successful operation of elecelectrodes with large soft-carbon cores in an trio-arc lamps with alternating electric curalternating-current arc-inclosed lamp, and rents, it has been found desirable, and in Fig. 4 is a similar view of the electrodes of 20 fact necessary, to employ electrodes having an open-air alternating-current lamp. cores of soft carbon the particles of which A represents an alternating-current electraverse the space intervening between the trio-arc lamp. The lamp is provided with carbons and serve, in effect, to form a conelectromagneticregulatingmechanism which ducting-bridge from one carbon to the other may be of any desired construction capable 25 for the alternating currents and thus prevent of drawing and regulat-ingalong are between the constant breaking of the arc and the 0011- the carbons, the are being confined within a sequent unsteadiness of the light. close arc-inclosing globe 13, supported in a Cored carbons which have been and are suitable manner by the lamp-casing. The now being used in the ordinary open-airalterinner arc-inclosin g globe is itself inclosed by 30 nating-current arc-lamps are constructed a large outer globe C, as is usual with modwith a core of about one-eighth of an inch in ern arc-inclosed electric-arc lamps. diameter. In suchlampsthe arcis aboutone- Each electrode D E of the lamp is consixteenth of an inch in length and is mainstructed with a small longitudinal bore or tained by a current of about thirty volts and hole a, which is preferably about one-six- 3 5 fifteen amperes. The are thus produced is teenth of an inch in diameter, or about oneso short and thick that it is prevented from half the diameter of the cores of the cored entering to any appreciable distance within carbons which have heretofore been used. the cores of the carbons, and hence the feed The core is filled with carbon which is much and consumption ofthe carbons are mainsofter than the body of the electrode.

40 tained sufficiently uniform to insure a light In the operation of arc-lamps of this type sufficiently uniform and constant in its brilthe carbons are maintained normally sepaliancy to answer the requirements in comrated by a space of about three-eighths of an mercial use. inch, which requires an expenditure of an In the attempts which have been made to electromotive force of about eighty volts and 45 operate arc-inclosed alternating-current arca current of about five amperes to maintain 5 lamps it has been found impracticable to use the are between the carbons thus separated. cored carbons of the construction heretofore In the attempts which have been made to use in use, owing to the extreme fluctuations of ordinary cored carbons in this type of arc the light which resultfrom the employment lamp it was found that the excessively long 1 50 of such carbons and also to the fact that the and attenuated are which it is necessary to produce and maintain would center itself on the adjacent ends of the carbons, and the opposite ends of the arc would gradually eat their way into the cores of the carbons instead of eating and wearing away the ends of the carbons uniformly, with the result that as the carbons were fed together the ends of the are would be concealed within the large cores thus eaten away and operate to materially diminish the amount of light emitted by the adjacent ends of the carbons.

The angle of the rays of light with a long are between electrodes having cores of oneeighth of an inch in diameter and burned in an arc-inclosing globe will be about one hundred and lifteen degrees. These remarks apply to a considerable extent also to an openair alternating-current lamp employing electrodes with large cores, the arc in the latter case being very short and the normal angle of the rays of light being about ninety-five degrees. In both cases the rapidly and abundantly escaping carbon particles from the soft cores will become lodged upon and form a coating within the globe and thus obscure the light.

By making the soft cores of the electrodes very small via, about one-sixteenth of an inch in diametera minimum amount of line carbon particles will be liberated, just about enough to maintain the cond noting-bridge between the ends of the carbons and insure the continuity of the arc. The small amount of carbon particles discharged from the small cores in a given length of time as compared with the large amount emitted from large cores such as heretofore employed will be entirely consumed by the intense heat of the inclosed are, and no black ash or sediment will collect within the globe, and the latter will not therefore be given a semitranslucent coating, such as occurs when electrodes with large cores are employed.

lVith electrodes having soft-'nrbon cores of less diameter than the normal, such as I propose to employ, the consumption of the body of the electrode and its core will be practically uniform, the wasting away of the core being commensurate with that of the body of the carbon. The electrode ends will therefore remain a uniform distance apart during the continuance of the normal are. The light-giving capacity of the arc will not be diminished by the entrance of the arcwithin the bores of the electrodes, (the ends of the body of the electrode being always practically llnsh with end of the core,) as has been ere pcrienced with electrodes having large cores, and the maximum angle of about one hundred and forty degrees of the rays of light from the are will remain constant. I also lind the proportion above mentioned between the body of the carbon and core to be valuable when used as the lower electrode for a continuoim current are-inclosed clcctricarc lamp in that the spinning of the are, one of the most objectionable features of the hing-are lamp now so generally used, reduced to a minimum. The conditions, of course, are the same as in the alternating-current lamp in regard to the discoloration of the globe and unstez'uliness of the light with. the use of electroifles having cores of greater diameter than the length of the normal are, but at the same time the advantage of acored carbon to concentrate the arc in the con ter of the electrodes is obtained. Two of these carbons are new ssary for an alternating-current arc-lamp to produce the best results, but for a crmtinuens-current arc-lamp one such carbon only is necessary, preferably the lower carbon, al though an upper carbon of this type could be used, or both upper and lower, but, asabove explainethcne is sullicient witha continuous current.

llly improvement, though simple, is of git-cal, inuportance in insuring the successful opera tion of altcrnating-current arc-hiclosed electric-arc lamps, and by means of it annoying detects and objections heretofore encountered will be successfully obviated.

llaving fully described my invention, what I claim as new, and desire to secure by Let-- ters Patent, is-

The combination with an are-inclosed alternating-currcnt arc-lmnl'i, of cored carbons the cores of which are ene-sixteenth of an inch in diameter or less, substantially as set forth.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

GlCUltti-E lit. ll Gills. Witnesses:

Snnnoon tinny, J. N. San. 

